scholarly journals On the influence of climatic factors on the ratio between the cosmogenic isotope 14C and total carbon in the atmosphere in the past

2014 ◽  
Vol 41 (3) ◽  
pp. 216-222 ◽  
Author(s):  
Igor Koudriavtsev ◽  
Valentin Dergachev ◽  
Yury Nagovitsyn ◽  
Maxim Ogurtsov ◽  
Högne Jungner
Keyword(s):  
Solar Activity ◽  
Co2 Concentration ◽  
Galactic Cosmic Rays ◽  
Activity Level ◽  
Total Carbon ◽  
Solar Modulation ◽  
Time Interval ◽  
Model Calculations ◽  
Cosmogenic Isotope ◽  
The Past

Abstract Radiocarbon 14C is a cosmogenic isotope, which is most extensively used by scientists from a wide variety of fields. Its rate of generation in the atmosphere depends on solar modulation and thus, studying 14C concentration in natural archives, one can reconstruct solar activity level in the past. The paper shows results of box-model calculations of generation of the 14C isotope in the atmosphere and its relative abundance during the time interval 1389–1800 AD, taking into account influence of changing climate. This interval includes the deep minimum of solar activity and period of significant change in atmospheric concentration of CO2 and global temperature. The performed analysis showed that concentration of 14C in the atmosphere reflects not only variations of the galactic cosmic rays intensity but as well changes of temperature and atmospheric CO2 concentration. It is shown that the decrease in CO2 concentration in the atmosphere during 1550–1600 can be connected with absorption of CO2 by the ocean surface layer. Thus, taking into account the climatic changes is an important condition for the reconstruction of solar activity in the past using data based on cosmogenic isotopes.

Atmospheric production and transport of 7Be activity by cosmic rays: Modelling with the chemistry-climate model SOCOLv3.0 and comparison with direct measurements

2021 ◽  
Author(s):  
Kseniia Golubenko ◽  
Eugene Rozanov ◽  
Genady Kovaltsov ◽  
Ari-Pekka Leppänen ◽  
Ilya Usoskin
Keyword(s):  
Cosmic Rays ◽  
Climate Changes ◽  
Climate Model ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Cosmogenic Isotopes ◽  
Cosmogenic Isotope ◽  
The Past ◽  
Direct Measurements ◽  
First Results

<p>We present the first results of modelling of the short-living cosmogenic isotope <sup>7</sup>Be production, deposition, and transport using the chemistry-climate model SOCOLv<sub>3.0</sub> aimed to study solar-terrestrial interactions and climate changes. We implemented an interactive deposition scheme,  based on gas tracers with and without nudging to the known meteorological fields. Production of <sup>7</sup>Be was modelled using the 3D time-dependent Cosmic Ray induced Atmospheric Cascade (CRAC) model. The simulations were compared with the real concentrations (activity) and depositions measurements of <sup>7</sup>Be in the air and water at Finnish stations. We have successfully reproduced and estimated the variability of the cosmogenic isotope <sup>7</sup>Be produced by the galactic cosmic rays (GCR) on time scales longer than about a month, for the period of 2002–2008. The agreement between the modelled and measured data is very good (within 12%) providing a solid validation for the ability of the SOCOL CCM to reliably model production, transport, and deposition of cosmogenic isotopes, which is needed for precise studies of cosmic-ray variability in the past. </p>

Data-driven modeling decadal-to-centennial ENSO variability and its response to external forcing

2021 ◽  
Author(s):  
Aleksei Seleznev ◽  
Dmitry Mukhin ◽  
Andrey Gavrilov ◽  
Alexander Feigin
Keyword(s):  
Co2 Concentration ◽  
Data Driven ◽  
Time Interval ◽  
Solar Forcing ◽  
Russian Science ◽  
Dynamical Mechanism ◽  
Enso Variability ◽  
The Past ◽  
Sst Variability ◽  
Data Driven Modeling

<p>We investigate the decadal-to-centennial ENSO variability based on nonlinear data-driven stochastic modeling. We construct data-driven model of yearly Niño-3.4 indices reconstructed from paleoclimate proxies based on three different sea-surface temperature (SST) databases at the time interval from 1150 to 1995 [1]. The data-driven model is forced by the solar activity and CO2 concentration signals. We find the persistent antiphasing relationship between the solar forcing and Niño-3.4 SST on the bicentennial time scale. The dynamical mechanism of such a response is discussed.</p><p>The work was supported by the Russian Science Foundation (Grant No. 20-62-46056)</p><p>1. Emile-Geay, J., Cobb, K. M., Mann, M. E., & Wittenberg, A. T. (2013). Estimating Central Equatorial Pacific SST Variability over the Past Millennium. Part II: Reconstructions and Implications, Journal of Climate, 26(7), 2329-2352.</p>

Prediction of upcoming grand episodes of solar activity

2018 ◽  
Vol 13 (S340) ◽  
pp. 325-326
Author(s):  
G. L. Jayalekshmi ◽  
P. R. Prince
Keyword(s):  
Solar Activity ◽  
Active Regions ◽  
Phase Changes ◽  
Activity Level ◽  
Time Interval ◽  
The Sun ◽  
Strong Magnetic Fields ◽  
Periodicity Analysis ◽  
Long Time ◽  
Grand Minima

AbstractSunspots are active regions on the surface of the Sun having strong magnetic fields. Activity level of the Sun shows long-time scale phenomena known as grand episodes-Grand maxima and Grand minima. Present study examines grand episodes shown by sunspot numbers (1090-2017), using methods of wavelet transform and sinusoidal regression. Time interval analysed includes two grand maxima and four grand minima. Interval in between grand episodes are regular oscillations. Phase changes found from periodicity analysis clearly show the presence of upcoming grand episodes. The forthcoming grand episodes are suggested to be two grand minima which are likely to occur between the years 2100-2160 and 2220-2300.

scholarly journals Long-term variations of the mesospheric wind field at mid-latitudes

2007 ◽  
Vol 25 (8) ◽  
pp. 1779-1790 ◽  
Author(s):  
D. Keuer ◽  
P. Hoffmann ◽  
W. Singer ◽  
J. Bremer
Keyword(s):  
Solar Activity ◽  
Wind Field ◽  
Meridional Wind ◽  
Time Interval ◽  
Wind Component ◽  
Model Calculations ◽  
Measuring Techniques ◽  
Long Term Trends ◽  
Solar Influence

Abstract. Continuous MF radar observations at the station Juliusruh (54.6° N; 13.4° E) have been analysed for the time interval between 1990 and 2005, to obtain information about solar activity-induced variations, as well as long-term trends in the mesospheric wind field. Using monthly median values of the zonal and the meridional prevailing wind components, as well as of the amplitude of the semidiurnal tide, regression analyses have been carried out with a dependence on solar activity and time. The solar activity causes a significant amplification of the zonal winds during summer (increasing easterly winds) and winter (increasing westerly winds). The meridional wind component is positively correlated with the solar activity during summer but during winter the correlation is very small and non significant. Also, the solar influence upon the amplitude of the semidiurnal tidal component is relatively small (in dependence on height partly positive and partly negative) and mostly non-significant. The derived trends in the zonal wind component during summer are below an altitude of about 83 km negative and above this height positive. During the winter months the trends are nearly opposite compared with the trends in summer (transition height near 86 km). The trends in the meridional wind components are below about 85 km positive in summer (significant) and near zero (nonsignificant) in winter; above this height during both seasons negative trends have been detected. The trends in the semidiurnal tidal amplitude are at all heights positive, but only partly significant. The detected trends and solar cycle dependencies are compared with other experimental results and model calculations. There is no full agreement between the different results, probably caused by different measuring techniques and evaluation methods used. Also, different heights and observation periods investigated may contribute to the detected differences.

scholarly journals Solar rotational cycle in lightning activity in Japan during the 18–19th centuries

2018 ◽  
Vol 36 (2) ◽  
pp. 633-640 ◽  
Author(s):  
Hiroko Miyahara ◽  
Ryuho Kataoka ◽  
Takehiko Mikami ◽  
Masumi Zaiki ◽  
Junpei Hirano ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Rotation ◽  
Galactic Cosmic Rays ◽  
Activity Level ◽  
Lightning Activity ◽  
Activity Levels ◽  
Rotational Period ◽  
Solar Activity Level ◽  
The Impact

Abstract. Thunderstorm and cloud activities sometimes show a 27-day period, and this has long been studied to uncover a possible important link to solar rotation. Because the 27-day variations in the solar forcing parameters such as solar ultraviolet and galactic cosmic rays become more prominent when the solar activity is high, it is expected that the signal of the 27-day period in meteorological phenomena may wax and wane according to the changes in the solar activity level. In this study, we examine in detail the intensity variations in the signal of the 27-day solar rotational period in thunder and lightning activity from the 18th to the 19th centuries based on 150-year-long records found in old diaries kept in Japan and discuss their relation with the solar activity levels. Such long records enable us to examine the signals of solar rotation at both high and low solar activity levels. We found that the signal of the solar rotational period in the thunder and lightning activity increases as the solar activity increases. In this study, we also discuss the possibility of the impact of the long-term climatological conditions on the signals of the 27-day period in thunder/lightning activities. Keywords. Meteorology and atmospheric dynamics (lightning)

Fluctuations of atmospheric carbon-14 concentrations during the past century

1971 ◽  
Vol 321 (1544) ◽  
pp. 105-127 ◽  
Keyword(s):  
Solar Activity ◽  
Production Rate ◽  
Cosmic Ray ◽  
Solar Modulation ◽  
Past Century ◽  
Activity Maximum ◽  
Carbon 14 ◽  
The Past ◽  
Natural Carbon ◽  
Atmospheric Carbon

Variations in atmospheric carbon-14 concentrations during the past century have been studied through the analyses of wines, spirits and plant seeds. The results reveal that short-term fluctuations of carbon-14 concentrations have occurred which are negatively correlated with solar activity. Maximum correlation occurs with carbon-14 concentration minima preceding sunspot maxima by one year. The overall magnitude of the fluctuations, 3 % of the natural carbon-14 concentration, appears too large to be attributed to variations in the isotope production rate by solar modulation of the galactic cosmic ray flux. It is proposed that the fluctuations are the result of solar-sensitive mixing of stratospheric and tropospheric air masses through variations of the incident ultraviolet and corpuscular radiation over each solar cycle. Theoretical considerations require that stratospheric carbon-14 levels fluctuate in direct correlation with solar activity. These variations of natural carbon-14 activities in the troposphere represent a significant deviation from the basic assumption of the radiocarbon dating method and may introduce further uncertainty in the dating of ‘young’ materials. In addition, they endorse the universal use of the N. B. S. modern standard in carbon -14 assay. A long-term decrease in tropospheric carbon-14 concentrations was also observed and is attributed to a reduction in the mean production rate of carbon-14 through enhanced solar activity.

scholarly journals A reconstruction of radiocarbon production and total solar irradiance from the Holocene <sup>14</sup>C and CO<sub>2</sub> records: implications of data and model uncertainties

2013 ◽  
Vol 9 (2) ◽  
pp. 1165-1235 ◽  
Author(s):  
R. Roth ◽  
F. Joos
Keyword(s):  
Solar Activity ◽  
Carbon Cycle ◽  
Solar Irradiance ◽  
Total Solar Irradiance ◽  
High Solar Activity ◽  
Solar Modulation ◽  
Total Production ◽  
Instrumental Data ◽  
The Holocene ◽  
The Past

Abstract. Past atmospheric CO2 concentrations reconstructed from polar ice cores combined with its Δ14C signature as conserved in tree-rings provide important information both on the cycling of carbon as well as the production of radiocarbon (Q) in the atmosphere. The latter is modulated by changes in the strength of the magnetic field enclosed in the solar wind and is a proxy for past changes in solar activity. We perform transient carbon-cycle simulations spanning the past 21 kyr using Bern3D-LPX, a fully featured Earth System Model of Intermediate Complexity (EMIC) with a 3-D ocean, sediment and a dynamic vegetation model. Using the latest atmospheric IntCal09/SHCal04 radiocarbon records, we reconstruct the Holocene radiocarbon fluxes and the total production rate. Our carbon-cycle based modern estimate of Q ≈ 1.7 atoms cm−2 s−1 is lower than previously reported by Masarik and Beer (2009) and more in line with Kovaltsov et al. (2012). Q is then translated into the solar modulation potential (Φ) using the latest geomagnetic field reconstruction and linked to a recent reanalysis of early instrumental data. In contrast to earlier reconstructions, our record suggests that periods of high solar activity (>600 MeV) were quite common not only in recent millennia but throughout the Holocene. Solar activity in our decadally-smoothed record is during 28% of the time higher than the modern average of 650 MeV during the past 9 ka. But due to considerable uncertainties in the normalization of Φ to instrumental data, the absolute value of Φ remains weakly constrained. Further, our simulations with a spatially resolved model (taking the interhemispheric Δ14C gradient into account) show that reconstructions that rely on the Northern Hemisphere 14C record only are biased towards low values during the Holocene. Notable deviations on decadal-to-centennial time scales are also found in comparison with earlier reconstructions. In a last step, past total solar irradiance (TSI) is quantified using a recently published Φ-TSI relationship yielding small changes in Holocene TSI of order 1 W m−2 with a Maunder Minimum irradiance reduction of 0.85 ± 0.17 W m−2. Future extension of TSI using autoregressive modeling suggest a declining solar activity in the next decades towards average Holocene conditions. Past TSI changes are finally translated into changes in surfaces atmospheric temperature (SAT) by forcing the Bern3D-LPX model with our new TSI record, yielding SAT anomalies of less than 0.1 K.

scholarly journals Variation of Radiocarbon Content in Tree Rings During the Maunder Minimum of Solar Activity

Radiocarbon ◽  
1992 ◽  
Vol 34 (2) ◽  
pp. 213-217 ◽  
Author(s):  
G. E. Kocharov ◽  
A. N. Peristykh ◽  
P. G. Kereselidze ◽  
Z. N. Lomtatidze ◽  
R. Ya. Metskhvarishvili ◽  
...  
Keyword(s):  
Solar Activity ◽  
Tree Rings ◽  
Ice Cores ◽  
Maunder Minimum ◽  
Solar Modulation ◽  
Time Interval ◽  
Annual Data ◽  
Polar Ice

We present here annual data on 14C abundance in tree rings during the Maunder minimum of solar activity (ad 1645–1715). We show that the solar modulation persisted during the minimum. We also compare these data with measurements of 10Be concentration in dated polar ice cores and with records of aurorae recurrence during this time interval.

Radiocarbon in tree-rings reveals the solar 11-yr cycle over the last millennium

2020 ◽  
Author(s):  
Lukas Wacker ◽  
Nicolas Brehm ◽  
Alex Bayliss ◽  
Marcus Christl ◽  
Hans-Arno Synal ◽  
...  
Keyword(s):  
Solar Activity ◽  
Tree Rings ◽  
Ice Cores ◽  
Cosmogenic Nuclides ◽  
Ice Age ◽  
General Level ◽  
Solar Modulation ◽  
Last Millennium ◽  
The Past ◽  
Tree Ring Data

&lt;p&gt;The influence of solar variability on the Earth&amp;#8217;s climate is a major subject of interest for understanding past and predicting future climate changes. While the observational record of solar activity (e.g. sunspots) covers only the last about 400 yr, cosmogenic nuclides stored in tree rings (&lt;sup&gt;14&lt;/sup&gt;C) or ice cores (&lt;sup&gt;10&lt;/sup&gt;Be, &lt;sup&gt;36&lt;/sup&gt;Cl) are used as proxies for solar activity and allow solar reconstructions reaching much further back in time &lt;sup&gt;1-3&lt;/sup&gt;. Major drawbacks of cosmogenic nuclide based solar reconstructions are the presence of weather-induced noise (e.g. &lt;sup&gt;10&lt;/sup&gt;Be in ice cores) or the low temporal resolution of long precisely dated records (&lt;sup&gt;14&lt;/sup&gt;C in tree rings). Here, we present a continuous, annually resolved &lt;sup&gt;14&lt;/sup&gt;C record from precisely dated tree rings covering the past about 1&amp;#8217;000 yr (969-1933 AD) comprising almost 1&amp;#8217;300 highest-precision &lt;sup&gt;14&lt;/sup&gt;C measurements. The annually resolved &lt;sup&gt;14&lt;/sup&gt;C record adds significantly to the radiocarbon calibration curve&lt;sup&gt;4&lt;/sup&gt;, which has hitherto been based mainly on decay counting measurements. A multi box carbon cycle model is used to extract annual &lt;sup&gt;14&lt;/sup&gt;C production changes from the tree ring data. The resulting high-resolution record of &lt;sup&gt;14&lt;/sup&gt;C production is then used to reconstruct the solar modulation parameter over the last millennium. The comparison of solar modulation with global temperature provides evidence that low solar activity could have caused the temperature reduction during the Little Ice Age. The &lt;sup&gt;14&lt;/sup&gt;C record further reveals for the first time the presence of the eleven-year solar cycle over the past 1&amp;#8217;000 yr. The amplitude of this so called Schwabe cycle is found to correlate with the general level of the solar modulation with high amplitudes during periods of strong solar modulation and vice versa.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;sup&gt;1&lt;/sup&gt; Bard, E., Raisbeck, G., Yiou, F. &amp; Jouzel, J. (2000) Solar irradiance during the last 1200 years based on cosmogenic nuclides. Tellus Series B-Chemical and Physical Meteorology 52, 985-992.&lt;/p&gt;&lt;p&gt;&lt;sup&gt;2&lt;/sup&gt; Muscheler, R. et al. (2007) Solar activity during the last 1000 yr inferred from radionuclide records. Quaternary Science Reviews 26, 82-97.&lt;/p&gt;&lt;p&gt;&lt;sup&gt;3&lt;/sup&gt; Usoskin, I.G. (2017) A history of solar activity over millennia, Living Rev. Sol. Phys. 14, 3.&lt;/p&gt;&lt;p&gt;&lt;sup&gt;4&lt;/sup&gt; Reimer, P. J. et al. (2013) Intcal13 and Marine13 Radiocarbon Age Calibration Curves 0-50,000 Years Cal Bp. Radiocarbon 55, 1869-1887.&lt;/p&gt;

scholarly journals Reconstruction of solar activity based on 14C and other isotope profiles in lunar regolith

2021 ◽  
Vol 2103 (1) ◽  
pp. 012007
Author(s):  
D Frolov ◽  
A Pavlov ◽  
V Ostryakov ◽  
A Konstantinov ◽  
G Vasilyev ◽  
...  
Keyword(s):  
Solar Activity ◽  
Time Scales ◽  
Nuclear Reactions ◽  
Lunar Regolith ◽  
Ice Cores ◽  
Calibration Procedure ◽  
Nuclear Interaction ◽  
Correction Method ◽  
Galactic Cosmic Rays ◽  
Solar Modulation

Abstract The Moon might be considered as an integral detector of Galactic Cosmic Rays (GCR) as it contains on its surface cosmogenic isotopes produced by nuclear reactions. Since the retrieval of lunar regolith cores by Apollo missions, there were numerous attempts to measure concentrations and depth profiles of those isotopes and reconstruct the level of cosmic radiation at 1AU at various time scales, ranging from thousands to millions of years. The data also contains encoded levels of solar activity, as the Sun affects the differential flux of GCRs in a well-known manner. All those attempts showed that our nuclear interaction codes, GEANT4 for example, need corrections to describe the lunar data, be it tweaking of cross-sections or any other methods. There are also such archives on Earth: ice cores and trees. Based on terrestrial modulation potential reconstruction we try to calibrate GEANT4 code in a transparent manner, and also present our estimates on the solar activity on time scales of 0.02 and 3 Myrs. The estimates made using our calibration procedure show values consistent with modern understanding of history of solar modulation potential, and demonstrate the necessity to establish an agreed correction method for the analysis of lunar data. We also compare our results and method with another estimation of solar modulation potential during the last 1 Myr.

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